Fake edit: ooh, they don't have enough problems yet and E_NOT_ENOUGH_REGEXP, so what about..."(Nye |)(Troms|Finn)(troms|finn|)(mark|)"
(and I'd suggest making the quotes part of the name to avoid it being parsed wrongly by buggy code...)

(fake fake edit: can someone please add the look-ahead to allow Troms alone but not Finn alone, based on the list of choices)
(non-fake edit: and also to forbid Tromstroms and Finnfinn... although that does have a nice ring...)